Spark plug



April v16, 1935. lRvlN ET AL 1,998,158

SPARK PLUG Filed Aug. 18, 1931 l N V E N T ORS W' BY ,wa

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Patented Apr. 16, 1935 PATENT oir-Fics l 1,998,158 v SPARK PLUGTheodorelrvin and John A. Pearce, v Philadelphia, Pa.

Application August is, 1931, Serin No. 557,892y

4 Claims. (Cl. 12B-169) v This invention relates to an improved ysparkand more especially to aspit re' type, wherein the lower end of thecasing of the spark plug, that is the casing for the reception of theporcelain holder for the electrode is closed over the electrode, withthe exception of providing tWO diametrically opposite openings in theclosed end ci the casing to provide outlets, through whichtheexplodedgases collected in a chamber caused to formed in the lowerend of the casing adjacent terminal of the electrode may escape.

` any-desired,modification of details' and proportions maybe made intheconstruction of the appliance according to circumstances. f

The invention comprises further features and combination of parts toY behereinafter set forth, sh wn in the drawing and claimed.

ln the drawing:-

Figure l is a vertical sectional view through the improved spark plugconstructed in accordance with the invention.

Figure 2 is an end View showing the diametrically opposite openings forthe escape of the exploded gases.

Figure 3 is an enlarged detail perspective view of the lower end of thecasing of the spark plug more clearly showing the diametrically oppositeopenings.

Referring to the drawing l identies a casing of the spark plug, whichmay be made of any suitable metal, for housing a porcelain holder 2, whin turn supports an electrode 3. This casing is provi-:led with threads5 for engaging a tapped opening 5 formed in the wall of the combustionchamber of an internal combustion engine (not shown). The porcelainholder, While it may be of any desired exterior contour is preferablyprovided with a conical portion 'l merging into a shoulder 8, againstwhich a ring 9 of any suitable metal preferably copper may engage. A nutl5 nts telesccpically over the upper end ci the porcelain holder andagainst the ring and is provided with exterior threads ll, forengagement with the internal threads I2 of the spark plug casing. Theelectrode is made of any suitable electrical conducting metal, and hasits terminal spaced a short distance from a screw terminal i3, which isthreaded in the lower end of the spark plug casing so as to provideasparking gap. Also threaded in to the lower end of the spark plug casingis a lock screw l, which retains the screw terminal in locked position.A

construction and arrangement oi spark plug casing relative tc a copperring adjacent the inner end of the porcelain holder the gas chamber I8is caused tobe formed, andv into which the usual gas charge on theinterior of the combustion chamber is compressed, on theV compressionstroke of the piston y(not shown) Yof the engine (not shown), wherebywhen a charge of current passes across the gap between the terminal cithe electrode and the screw terminal the compressed gases are explocled. .1, n 4

In. this case .the exploded gases discharge through the diametricallyopposite openings, and thereby impart movement to the engine piston due'to the force of the explosion and the expanded gases. By thisconstruction and arrangement the spark plug obviously as characterizedis the spit nre type.

The invention having been set forth, what is claimed is:

1. In a spark plug, the combination with a casing provided with asubstantially closed end, the wall of said closed end being of an abruptconical formation, of an electrode holder operatively tting closelyWithin the lower portion of said casing and carrying an electrodelongitudinally centrally of the holder with an end protruding beyond theend of the holder, the end of the holder being dished to expose asubstantial portion of the end of the electrode; means within the casingbetween the end of the holder and the wall of said closed end acting tocreate a gas chamber between the end of the holder and the wall of saidclosed end, and into which one end of the electrode terminates, aterminal screw threaded through the apex of the conical closed endconstituting an opposite electrode axially aligned with the extremity ofthe first electrode and being spaced therefrom causing a sparking gap tobe formed, said terminal screw electrode being adjustable to increase ordecrease the sparking gap, a locking screwthreaded through the apex ofthe conical closed end and against the terminal screw electrode to lockthe latter in adjusted positions and against displacement incident tovibrations, said conical closed end having diametrically oppositedischarge openings with their axis at direct right angles to the conicalwall of the closed end and at acute angles to the first electrode,whereby upon a compression of the discharge in the chamber with asubsequent explosion of the charge by a spark across the gap, theexploded gases discharge divergently from the chamber and from the firstelectrode and away from the gap immediately incident to the gap therebypreventing collection of carbon in the gap and between the adjacent endsof both electrodes.

2. In a spark plug, a casing provided with a substantially closed abruptconical end, the in-v ner surface of said end being substantially of asimulating conical formation, a gasket conforming to and seated uponsaid inner simulating conical surface, said casing having a boreextending from said inner conical surface of the closed end forsubstantially one half the length of the casing, an electrode holderfitting closely within substantially the full length of said bore withits inner end conforming to and engaging said gasket thereby spacing theinner end of the holder from said inner conical surface of the closedend creating a gas chamber, means cooperating with the other end of theholder and casing for bearing the inner end of the holder tight againstthe gasket, thereby preventing any gases seeping between the holder andthe bore of the casing, an electrode centrally of the holder, a secondelectrode carried by the apex of said closed end and its end spacedYfrom the rst electrode to create a sparking gap, said closed end of thecasing having opposite discharge openings with their axis substantiallyat right angles to the conical wall of the closed end and at acuteangles to the rst electrode, whereby upon an explosion of the charge inthe chamber, the gases discharge divergently from the chamber and awayfrom the gap between the first and second electrodes.

3. In a spark plug, a casing provided with a substantially closed abruptconical end and having a bore extending from said end for substantiallyone half the length of the casing, an electrode holder tting Withinsubstantially the full length of the bore with its inner end spaced fromthe inner surface of the closed end creating a gas chamber, means forpreventing seeping of gases between the wall of the bore and the holder,an electrode centrally of the holder with its inner end exposed in saidgas chamber, a screw electrode threaded through the apex of the closedend, a locking screw threaded into said apex against and locking thesecond electrode in spaced relation to the first electrode to create asparking gap in said chamber, said closed end having opposite openingswith their axis substantiallyA at right angles to the wall of the closedend and at acute angles to the rst electrode, whereby upon an explosionof the charge in the chamber the gases may discharge divergently awayfrom the gap and through the openings.

4. A spark plug comprising a casing, and means for installing saidcasing in the cylindrical wall of an internal combustion engine with oneend exposed in the cylinder, said casing having in the interior thereofan enclosed firing chamber, and having in the exposed end thereof aplurality of ports which enter the ring chamber in divergent positionstherefrom at diametrically opposite points of the center of the bottomwall of the chamber, sparking terminals exposed in'this firing chamber,one being in the center of the bottom wall of the chamber between theports, and a locking plug fastened in the center of the bottom wall ofsaid chamber against one of said sparking terminal elements to lock thelatter in position.

THEODORE IRVIN.

JOHN A. PEARCE.

